1. Field of the Invention
The present invention relates to a method of manufacturing electronic components, and more particularly, to a method of manufacturing a plurality of electronic components including a step of cutting a mother substrate, having an electrode on its surface, along predetermined cutting lines to thereby produce a plurality of individual electronic components each having an electrode exposed on opposed cut surfaces thereof.
2. Description of the Related Art
A well-known chip-type coil component in which an electrode pattern (thin-film coil pattern) is disposed on the surface of a substrate, is manufactured by cutting a mother substrate 51, which has a plurality of electrode patterns 52 formed thereon and is covered with an insulating and protective film 53 as shown in FIG. 7, along predetermined cutting lines A and B, thereby cutting out individual electronic components 54.
The insulating and protective film 53 is formed of, for example, a resin material such as a polyimide, or a glass material to achieve a desired surface smoothness, insulating properties, heat resistance, and suitability for micromachining required for the miniaturization of electronic chip components.
In a chip-type electronic component to be miniaturized, in particular, a chip-type coil component in which an electrode pattern (thin-film coil pattern) is disposed on a substrate, it is important to reliably provide a wide area for forming the electrode pattern in order to maintain and improve the performance of the component.
Accordingly, a dicing method for cutting with a dicing blade is used to cut out individual devices by cutting the mother substrate at predetermined positions.
This dicing method offers high working accuracy and can simultaneously cut the insulating and protective film. Also, this method does not require a cutting margin as is required in a scribe and break method. Further, this method allows the electrode pattern to be formed even on the outer peripheral part of the electronic chip component and ensures a wide area for use in forming the electrode pattern.
FIG. 8 is a cross-sectional view of an electronic component 54 which has been cut out from the mother substrate 51 shown in FIG. 7, in which outer electrodes 55 are arranged to be electrically connected to connecting electrodes 52a exposed on cut surfaces 51b.
In order to cut out the individual chip components 54 using the above-described dicing method so that the connecting electrodes 52a are exposed on the ends of each substrate 51a, it is necessary to cut the connecting electrodes (metal films) 52a over their full length across the overall width of the dicing blade in the case where the electrode patterns are formed as shown in FIG. 7. Since the cutting resistance of the connecting electrodes (metal films) 52a is generally greater than that of the mother substrate 51, the dicing blade wears significantly and experiences clogging. The clogging reduces the cutting force, which causes chipping of the mother substrate.
Furthermore, if adhesion between the connecting electrodes (metal films) 52a and the insulating and protective film 53 is not greater than adhesion between the mother substrate 51 and the insulating and protective film 53, peeling sometimes occurs not only at the insulating and protective film 53, but also at the connecting electrodes 52a during the step of cutting with the dicing blade, as shown in FIG. 9.
In addition, membrane stress produced during film formation sometimes remains in the connecting electrodes (metal films) 52a. As a result, the metal films 52a are more likely to peel when an external force is applied by cutting with the dicing blade.